Nucleic acid hybridization reactions are at the heart of a number of powerful assays used in molecular biology research and increasingly in diagnostic applications. Hybridization reactions typically require long incubation times, i.e. overnight. Recent work has demonstrated that a ribonucleoprotein and certain cationic detergents can increase hybridization rates several thousand fold such that the reaction will effectively go to completion in a few minutes. The overall goal of this project is to use this technology to develop high-speed nucleic acid hybridization procedures for use in solution and solid phase assays such as Southern blotting. To demonstrate the feasibility of this approach, we will couple this high-speed hybridization technology to a new streamlined method developed at Ambion for ribonuclease protection assays. We will use nucleic acid probes immobilized to beads to determine optimum conditions for high-speed hybridization. The results from these experiments will then be applied to the development of protocols for high-speed Southern and Northern hybridization procedures. The successful completion of this project will have major impact, both on the research and especially the diagnostic applications of nucleic acid hybridization assays.